- Categories · Computer Science-

2022

An introduction to tree data structures, covering essential terminology like roots, leaves, and children, with a primary focus on the properties and complexity of binary trees. Explores how their hierarchical nature and logarithmic depth potential offer efficient alternative to standard linear data structures like arrays and linked lists.

2021

Explore the fundamentals of Merge Sort, a stable and highly efficient divide-and-conquer sorting algorithm. This article provides a comprehensive overview, including pseudocode, in-depth algorithmic analysis with Master Theorem derivation, and fully corrected code implementations in Java and C. Learn why Merge Sort consistently delivers $O(n \log n)$ performance across all scenarios, though it requires $O(n)$ auxiliary space.

This article provides a comprehensive overview of the Quick Sort algorithm, a highly efficient comparison-based sorting method. It covers the core divide-and-conquer logic, analyzes its performance in best, worst, and average scenarios (ranging from $O(n \log n)$ to $O(n^2)$), and discusses critical optimization strategies like pivot selection methods (median-of-three, randomized). Complete with clear pseudocode and implementations in Java and C.

This article provides a comprehensive overview of Insertion Sort, a simple yet effective sorting algorithm. It details the algorithm's concept, analyzes its time and space complexity in best, worst, and average cases, and presents idiomatic implementations in both Java and C. Learn why Insertion Sort is adaptive and efficient for small or nearly sorted datasets.

2020

This article provides a comprehensive overview of Selection Sort, a simple comparison-based sorting algorithm. We explore its core steps - iterating to find the minimum element in the unsorted portion of a list and swapping it into its correct sorted position. The analysis details why Selection Sort is $O(n^2)$ time complexity for both average and worst cases due to nested loops, requiring minimal $O(1)$ extra space. We also explain why it is classified as an unstable sorting algorithm, demonstrated by a clear example where the relative order of equal elements is not preserved. A corrected Java implementation is included.

This guide covers essential searching algorithms—Linear and Binary Search. It details their logic, pseudocode, Java implementations, and complexities. Binary search's O(log n) efficiency on sorted collections is analyzed using the Master Theorem, and practical tips, including overcoming arithmetic errors and using built-in Java tools, are provided.

This post explores the application of numerical methods to analyze the initial growth trends of the COVID-19 outbreak using real-world data from Johns Hopkins CSSE. It utilizes a Quadratic Least Squares polynomial to model the time-series data of new confirmed cases, effectively smoothing inherent data noise. Subsequently, Richardson’s Extrapolation is applied to a 3-point midpoint formula to calculate the instantaneous rate of change (first derivative) of the new cases at various time intervals. The analysis reveals a significant deceleration in the growth rate over the studied period, suggesting the positive impact of early social distancing measures. The computational methods were implemented in MATLAB and Java, demonstrating robust modeling and high-precision results from low-order formulas.

This post explores key takeaways from Robert C. Martin's seminal book, "Clean Code - A Handbook of Agile Software Craftsmanship." It focuses on the crucial importance of writing readable and maintainable code to prevent technical debt. Key concepts discussed include the "Do One Thing" principle for functions, abstracting complexity across layers, prioritizing expressive code over comments, and adopting modern error handling. The post includes practical Python and pseudocode examples contrasting good and bad practices, with a final checklist summarizing core rules for naming, functions, comments, formatting, testing, and concurrency.

This post explores how equality operators differ across programming languages, focusing primarily on JavaScript's complex behavior. It explains why seemingly identical objects or arrays might not be considered equal due to reference-based comparison, contrasting JS with Ruby's structural comparison and Python's explicit 'is' operator for identity checks.

This article explores the fundamentals of operating system file systems, including file abstraction, metadata, hierarchical and acyclic directory structures, file operations (open/read/write), and various disk block allocation strategies (contiguous, linked, clustered, FAT) for optimal storage management and access efficiency.

This comprehensive guide explores the principles of virtual memory in operating systems, focusing on demand paging, page fault handling, and various page replacement algorithms like FIFO, LRU, Aging, Second-Chance, and Working Set. It analyzes the mechanics and trade-offs of each approach, as well as performance factors like memory allocation, thrashing, and optimal page size determination.

A comprehensive technical guide to Operating System memory management. This article explores the abstraction of physical RAM into logical address spaces, detailing program relocation, contiguous memory allocation algorithms (First Fit, Next Fit), the 50% Rule for fragmentation, and modern techniques like paging, segmentation, and their combination for efficient memory utilization and security.

A comprehensive guide to understanding deadlock in operating systems. This post defines deadlock, demonstrates how to model it using resource allocation graphs and state transitions, and covers various detection algorithms for both general and single-unit resources. It also explains dynamic deadlock avoidance, specifically the Banker's Algorithm, and effective strategies for deadlock prevention by breaking necessary conditions like hold-and-wait and circular wait.

2019

An in-depth explanation of concurrency issues in operating systems, focusing on critical sections and the requirements for synchronization solutions (mutual exclusion, deadlock avoidance, starvation prevention). The post explores process competition and cooperation (like the Producer-Consumer problem) and detailed mechanisms to resolve these issues, including hardware-level atomic operations, binary and general semaphores, busy waiting vs. blocking, and high-level synchronization constructs like Monitors and condition variables.

A comprehensive guide to understanding how operating systems schedule processes. It covers long-term and short-term schedulers, preemptive vs. non-preemptive scheduling, and various algorithms for batch (FIFO, SJN, SRTF), interactive (Round-Robin, Multilevel Feedback), and real-time processes (Rate-Monotonic, Earliest Deadline First). Includes performance analysis like average turnaround time and CPU utilization.

An in-depth look at core Operating Systems concepts related to processor management. This post covers the classic three process states (Running, Ready, Blocked) and transitions, the structure and management of the Process Control Block (PCB), the concept of timesharing via virtual CPUs, Resource Control Blocks (RCB), and a thorough explanation of threads (ULTs vs. KLTs) with memory segment visualizations.

An overview of the foundational components of a computer system and the multifaceted role of an operating system. This article explores how an OS functions as a bridge between hardware and software, providing crucial abstraction and virtualization layers to simplify complex operations and manage resources efficiently. It further discusses the distinct modes of operation—Kernel and User mode—essential for system security and stability.

A concise, interactive Git cheatsheet based on Learn Git Branching. Covers core Git commands for branching, committing, merging, rebasing, resetting, and cherry-picking with visual aids. Perfect for a quick, essential understanding of practical Git workflows. (This article is a tutorial-based guide and does not discuss algorithm complexity like time/space complexity.)

This article provides a comprehensive introduction to algorithm analysis, defining what algorithms are and distinguishing them from actual code implementations. It explores various algorithmic approaches, including deterministic, randomized, optimization, parallel, and distributed paradigms. Furthermore, it examines the critical resources consumed by algorithms—such as time, memory, power, bandwidth, circuitry, idleness, and load—and demonstrates how different data structure implementations (like array-based vs. linked lists) drastically affect performance for operations like insertion and retrieval.